1. Field of the Invention
The present invention relates to a data communication apparatus having an ITU-T (Telecommunication Standardization Sector of International Telecommunication Union) recommendation V.34 communication function.
2. Related Background Art
Conventionally, in the ITU-T recommendation V.34 communication, after a receiver receives a line probing signal and transmits an INFOh signal, and it shifts to reception of a primary channel equalizer training signal.
If the receiver fails to receive the primary channel equalizer training signal, it transmits a tone A signal and receives a tone B signal. Thereafter, the receiver transmits an INFOh signal and then shifts to reception of a primary channel equalizer training signal again. The INFOh signal transmitted at this time is the same as that previously transmitted.
In the prior art, however, when the second primary channel equalizer training signal is to be received, the same INFOh signal as in the first reception of the primary channel equalizer training signal is transmitted. For this reason, reception of the primary channel equalizer training signal often fails again. In this case, the initial identification timer (T1 timer) is up, resulting in a communication error.